jdk/test/hotspot/jtreg/compiler/loopopts/superword/TestLongReductionChain.java
2025-12-02 13:10:37 +00:00

86 lines
3.0 KiB
Java

/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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*
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
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*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package compiler.loopopts.superword;
import jdk.test.lib.Utils;
import java.util.Random;
/*
* @test
* @bug 8372451
* @summary Test long reduction chain. Triggered bug with long chain of dead ReductionVector
* vtnodes after optimize_move_non_strict_order_reductions_out_of_loop.
* @library /test/lib /
* @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:LoopUnrollLimit=1000 -XX:MaxVectorSize=8 -Xbatch
* -XX:CompileCommand=compileonly,${test.main.class}::test
* ${test.main.class}
* @run main ${test.main.class}
*/
public class TestLongReductionChain {
static int RANGE = 1024*8;
private static final Random RANDOM = Utils.getRandomInstance();
public static void main(String[] args) {
int[] aI = generateI();
int[] bI = generateI();
int gold = test(aI, bI);
for (int i = 0; i < 1000; i++) {
int result = test(aI, bI);
if (result != gold) {
throw new RuntimeException("wrong value");
}
}
}
static int[] generateI() {
int[] a = new int[RANGE];
for (int i = 0; i < a.length; i++) {
a[i] = RANDOM.nextInt();
}
return a;
}
// Test creates a very long reduction chain, especially with -XX:LoopUnrollLimit=1000.
// Limiting the reduction vectors to 2 elements gets us a very long chain -XX:MaxVectorSize=8.
// During VTransform::optimize this means a long chain of nodes needs to be found as dead.
// Before the fix, this took too many rounds, and we hit an assert.
static int test(int[] a, int[] b) {
int s = 0;
for (int i = 0; i < RANGE; i+=8) {
s += a[i+0] * b[i+0];
s += a[i+1] * b[i+1];
s += a[i+2] * b[i+2];
s += a[i+3] * b[i+3];
s += a[i+4] & b[i+4];
s += a[i+5] & b[i+5];
s += a[i+6] & b[i+6];
s += a[i+7] & b[i+7];
}
return s;
}
}